Spring sash balance



Dec. 8, 1942. J. B. JEssUP SPRING SASH BALANCE Filed Jan,A-15, 1941 INVENTOR.- z/m's'-5. ds-sae,

ATTORNEYS. v

PatentedfDec. 8,1942 I- sentir slash' BALANCE James B'. Y.e'ssllpl' Burbanlafalif., vassignerI to Duplex, Inc.; West" Hollywood, Calif., laco'rl'Jo-a ration of California Application January 15, 1941i, serai 510,374,484

4o1a'ims.- (o1. ifi-198) This invention relates to spring sash balances and comprises generallyV a'housing containing two sash balance units which are twins,one vfor balancing the upper sash ,and the other fertile lower sash. Each unit includes an axle within a drum journaled for rotation*y thereion 4 A cable or other exible member is wound on thedrum with itsfree end adapted to extend throughrfa cable opening or slot in theV housing for attachment to its respective sash. c A

A` spiral spring is arranged within the drum havingA its outer end connected theretoandits inner end connected tok the axle. Y.

I have found that in balances'such Aas IY have described, the cable maydbecrome jammedlbetween the members constituting .the-housing, which may have become sprung apart or otherwise separated, or the cable mayv suier undue wear with consequent damage thereto b'yf rubhing against portions of the housing.'

An object ofmy present invention is toleliminate the aforesaid disadvantages, by providing a new and novel means for securing togetherthe two separate members which compose thefhous'- ing, and which said means also 'constitutes a bearing member for the cable. f t

A further object of my invention'isv to provide in a device or the character described'a simplied construction of 'housing to contain 'and sup'- port the moving parts of the sash balance, therby achieving ease of manufacture'"and va'sseriloly as well as decreased cost of manufacturel A Still further bjeCt df my'lnvr'itl' IS t0 provide in a device of the character' described,

'a simplified form of housing which incorporates a combined fastening means between the 'com'- ponent parts of the housing'and a bearing mem'- ber yfor the cable, said bearing member'having a predetermined, critical location in respect to the` cable opening in the housing and thej'p'ath of travel of the cable', so that thec'able' mustof necessity bear against the said bearing member and thus be protected thereby.

Another object of my `invention is to provide in adevice ofthe character described, a small, compact, and relatively flat housing fora duplex adjustable sash balance which YpossessesA the characteristics of strength; 'simplicity,'and ease of assembly. From the form of housing which I have illustrated as my preferred embodiment, including, as aforesaid, a novel means jfor fastening together the parts constituting the housing in which the duplex balances are contained, and which said means also constitutes a bearing me'mberfor the cable which `travels -tangentially from the drum on which the cable is wound, I achievecertainy advantages notpossessed by former types of housings. `vItis essential to predetermine the relative positions and form of the component parts ofthe housing and of the combined fastening meanslxand bearing member in respect. to the position and 'movement of the exposed end of the'fcable, ardI achieve those 'ob- Ajects and advantageswith'my present 'invention 4a highly s'ati'sfactdr'y'l manner asA Will herein- 'af-ter become apparenti c VIn respect to the cable, the'use of tape or 'flexible wire or kother suitable material, would be other objects and laavantages win. become; ap-

parent from a further description of the invention in re'ferenc'eto the drawing. c

In the drawingz' Figure jliis va persp'ectiyefview Yof'a window frame assembly with my adjustable spring `sash balance installed.

c Figure2 isan enlarged front 'elevation of the adjustable spring sash balance asinstalled.

"Figure 3 Ais'a'vertical. section taken on the lline 3'-3 'of Figure 2'. f

Figure. ll isv a fragmentary sectional view-of V,one unit of ktheduplex type ofadjustable' spring "sash balance embodying my invention.

Figure 5 is a fragmentary cross-sectional view taken on the linek 5-"5of Figure4. c

A`wind'ow frame 'assembly lV of conventional construction includes a pulley stilee2' and-apartingjbead 3, a lower sash 4', an" upper sashr 5,- and oppositely disposed blindstops V(if.

My adjustable spring sash balance 1 is mounted in the pulley stile as shown'in detail in Figures l,2.2LIlCl 3.v 'I 4,

i For the purpose Yof installing :the sashy balance, 'a rectangular out Vis made through the vpulley stile of the same approximate-outside'di'- mensions as the housing-. It ispreferable to make this cut before`-th`ev frames are assembled. -The preferred form of my adjustable spring sashbalance comprisesahousing which includes afshallow box tlf-preferably formed by a die stamping operation. This vbox isV substantially rectangular in form and includes an integral back plate 9, integral side walls I0, and curved ends devices I4, whereby the box or housing'is secure ly fastened to the stile of the window frame, and the lower end preferably having the configuration as shown. Shallow inturned flanges disposed along Ia substantial portion of each side of the face plate constitute sides I5.

Spaced equi-distant from the ends of the back plate are two circular bosses upon which axles, not shown, may be mounted.

Although I prefer to make the device in duplex form, that is two units which are twins, it is only necessary to refer generally to one of the operatcable drum I'I which is inthe form of a cylin drical shallow cup formed with a slot at one point on its periphery. A flat spiral coil spring may be enclosed within the cable drum having its inner fend secured in a slot on the axle and its outer end secured in a: slot on Ythe cable drum, in a manner known to the art, and the spring may be tensioned'in any suitable manner.

Secured to the periphery of the cable drum is aflexible wire, tape, cable, or other suitable mem- --berl which has several turns around the drum and to the outer endof which isvattached a glider hook I9, or other means of attachment to a sash. The glider hook, an improved form of which comprises the subject Vmatter of my copending application Serial No. 327,155; filed April l, 1940, and issued September 16, .1941, as Patent No. 2,256,205, consists generally of an L shaped bracket member and a spring friction member attached thereto. As shown inY Figure 2 the glider hook is ordinarily attached to the lower corner of the sash in which position the spring frictionvally engages the stile.

It will be understood of course that' one cable I8 is carried by the upper one of the vtwo drums andV a separate cable is carried by the lower one of the two drums. The cables are wound onto the drums in different directions, so that the outer end of the upper 'cableis disposed adjacent one sideV of the housing while the outer end of the lower'cable is disposed adjacentthe other side of said housing. The exposed portion of the cable extends through the cable opening or slot I2'. Thel upper edge I2@ ofsaid cable slot is `formed in the side wall I at the point where the curvature of the end commences, and the lower `edge I2b is spaced a sufficient distance away so asrto permit the cable I8 which extends tangentiall'y from the cable drum to project through the .slot without causing any substantial contact with the edgesof the slot. As a `precaution against .the cable snagging on the edge I2b, I prefer to make it rounded and smooth.

To secure and retain the face plate in position uponthe-boxafter the operating parts of the balance v,have been properly assembled therein, I employlears or lugs which are 'formed integral -withand project from the edges of the side walls `of the box p There may be ainumber of these lugsat different locations, but a primary feature of my invention is the location of a lug along a projection of 'the tangent of the cable drum where that tangent crosses the junction between the edge |211 of the slot I2 and the rear of the face plate I3-. It is at this critical'locationwhere the cable Mmay become fouled in priordevices due to the housing being sprung or distorted andthe box and face plate becoming slightly separated and leaving a crevice for the cable to drop into if the cable is pulled to one side. This possibility Vhas been eliminated in my device by clamping the box and face plate at this point. They cannot become sprung or separated here by accidental jarring or distortion of the housing. In the form I have used as an example, the center of the lug is approximately 45 from the vertical center of the drum. It may be less if the end wall of the housing is spaced farther from the periphery of the drum.

The lug is bent over and pressed into a niche 2| formed in the face plate. The niche is preferably of the same outline as the lug, and its depth about equal to the thickness of the lug. This niche may be pressed inwardly from the face plate, and is struck to form a. slot 2Ia through which the lug may be inserted. The back of the depressed part which forms the niche provides a bearing 22 at the critical position described with reference to the positioning ofthe lug. This bearing is a smooth-raised surface with edges on both sides and one end rounded. l

It provides a means of keeping the cable spaced from the back of the faceplate I3 and 'consequently out ofthe region Where snagging of the cable at the junction of box and face plate might occur. I thus provide the double vfunction of tightly joining thebox andfaceplate at this critical intersection,A and by Vthe ksame means maintaining the cable away from-the point where it could be fouled, thus doubly'insuring its proper operation and long life. j Y

The bearing should be long enough to support the cable whendrawn to one side or the other of its intended vertical line of travel parallel to the vertical center of the drum.

The end ofthe face plate is formedwith notches 23 for greater freedom of thecable if drawn at a line oi the parallel of the face plate, but the bearing serves Ythe added function in this connection of preventing the cable from riding -on the edges of the notch;

In a duplex type of balance as illustrated, I utilize a fastening lug and bearing at each lower corner of the device, and preferably employsimilar fasteningimeans at other points as shown. vThis enables me to adequately secure the box and face plate together, without the fastening means protruding from the face plate.`

When installing, 'the cable o n one of the twin units is drawn out against the action of the spring and theglider hook at the end of the cable is screwed or nailed onto the sash as illustrated in Figure 2. The cable of the'other unit andl its corresponding glider hook are similarly attached to the other sash. The weight of the sash opposes the action of the' spring. Y

It will be found that'when the drum is rotated and the cable is retracted or extended tangentially from said drum, the cable will slide over and bear against and-be sustained by the bearing member 22 on 4the lower portion of the face plate I3, whenever the'cable winds oif the drum close to the rearpart ofthe face plate. There may betimes during operation, when the cable does not touch the'bearing, due to a helical winding of the cable on thedrum; but whenever the cable approaches the rear part of the face plate the bearing supports and protects it in the manner previously described. l l By my present invention I have made several improvements in the construction and operation of adjustable sash balances of the type described and more particularly in the construction and operation of the housing for containing such balances, in combination with the cable drum and the cable Wound thereon. I have particularly improved the means for fastening the box and the face plate oi the housing together and whereby the fastening means also constitutes a bearing member for the cables. Such construction is simple and inexpensive to manufacture as the bearing member performs a double function and may be substituted for what would normally be two members, to wit: a fastening means and a separate bearing means. Moreover, the location of independent fastening and bearing means at the identical location might present difficulties which have been avoided by my novel unitary means.

What I claim as my invention is:

1. In a spring sash balance including a rotatable drum having a exible member wound thereon with one end free for attachment to a sash: a housing to contain and support said drum and provide a bearing for the flexible member comprising, a box having an opening for the free end of the flexible member to travel through, a fastening lug projecting from the box adjacent the opening, and a face plate covering said box and provided with an inwardly depressed niche to receive said lug for fastening relationship between box and plate, said niche having a complementary smooth raised portion on the inner face of the f plate providing a bearing for the flexible member when moving onto and oil the drum, said lug, niche and bearing being located substantially along a projection of the tangent of the rotatable drum.

2. In a spring sash balance including a rotatable drum having a flexible member wound thereon with one end free for attachment to a sash: a housing to contain and support said drum and provide a bearing for the flexible member coml prising, a box having a slot for the free end of the exible member to travel through, a fastening lug projecting from the box adjacent the slot, and a face plate covering said box and provided with an inwardly depressed niche to receive said lug for fastening relationship between box and plate; said niche having a complementary smooth raised portion on the inner face of the plate providing a bearing for the flexible member when moving onto and 01T the drum through the slot, said lug, niche and bearing being located substantially along a projection of the tangent of the rotatable drum substantially where that tangent intersects the lower end of the slot.

3. In a spring sash balance including a rotatable drum having a exible member wound thereon with one end free for attachment to a sash: a housing to contain and support said drum and provide a bearing for the ilexible member comprising, a box having an opening for the free end of the iiexible member to travel through,- a fastening lug projectingfrom the box adjacent the opening, and a face plate covering said box and provided with an inwardly depressed niche to receive said lug for fastening relationship between box and plate, said niche having a complementary smooth raised portion on the inner face of the plate providing a bearing for the exible member when moving tangentially onto and oi the drum through the opening, said lug, niche and bearing being located on a projection of the tangent of the flexible member and substantially 45 from the vertical center of the drum.

4. In a spring sash balance including a rotatable drum having a flexible member wound thereon with one end free for attachment to a sash: a housing to contain and support said drum and provide a bearing for the flexible member comprising, a box having an opening for the free end of the flexible member to travel through, a face plate covering said box, a lug on said box and an inwardly depressed lug seat on said plate slotted at one end to receive said lug for securing the box and plate together, the back of said lug seat providing a raised bearing for the ilexible member when moving onto and off the rotatable drum through the said opening.

JAMES B. JESSUP. 

